lipscomb



Filed Oct. 22, 1952 INVENTOR. WILLIS L. LIPSCOMB.

AGENTS.

United States Patent for securement to vertical walls.

A primary object of this invention is to provide a cove lighting fixture or luminaire, wherein the cost of cleaning and other maintenance is reduced to the minimum.

Cleaning of wall supported luminaires has been, heretofore, a strong deterrent to the use of such lighting fixtures, preventing many owners from installing lighting systems which produce a foot-candlelevel of illumination that is deemed'necessary to satisfy the visual task requirements. The luminaire of my design has elimi nated most of the maintenance problems, therefore, makingthe use of cove lighting fixtures entirely practi' cable. It has been established that dirt and dust accumulation in a closed bottom, indirect type lighting fixture, is primarily caused by air currents flowing across the top and downwardly into the fixture. All air currents con- 7 tain dust particles which, whenrstriking a warm surface,

tend to attach thereto and, of course, when the movement of the air is slackened the dust therein tends to collect and settle on the adjacent surfaces. This is the reason why closed bottom indirect lighting fixturescollect dust so rapidly with the result that the light output from such fixtures rapidly depreciates. In the improved cove lighting fixture described herein, air currents are pe'r mitted to flow upwardly through spaces between light shielding slats at one side of an imperforate panel beneath the lamps, and permitting the air to blend in with a hot air pocket adjacent to the lamps to 'a very limited degree only, since most of the air moving upwardly between the louver-like slatsnever approaches the lamps or reflector surfaces. In other words, the hot air pocket around the lamps tends to become more or less distinct from the air currents. Since-these air currents do not strike the warm surfaces of the lamps or the warmer portions of the fixture, and since these air currents are'not unduly retarded at any time, the amount of dust which settles on the cove lighting fixture'is very small.

Another object of this invention is to provide a cove lighting fixture wherein the lighting is largely indirect and the lamps are completely shielded from view at any point either directly below or at the side of the lamp up to theline drawn horizontally through the lamp, and since these cove lighting fixtures are designed for place ment above the eye level in the room, the lamps remain completely invisible to persons sitting or standing in the room, this feature being accomplished while still allowing for air currents through the fixture as mentionedsin the immediately preceding paragraph.

. Another object of this invention is to provide a cove lighting fixture wherein no removal or displacement of any. part of the luminaire is required in order to gain access to thelamps for replacement thereof when necessary.

Yet another object of this invention is to provide a cove lighting fixture which is very easily cleaned when this is required, it being understood that dust will settle upon the fixture when the lamps are not in operation. It has been estimated that, where a considerable number of such fixtures are installed, a maintenance factor of better than eighty-five per cent ca n be attained for the cost of approximately five minutes of time per cove lighting fix- This compares very favorably with all ture, per year.

2,732,484 Patented Jan. 24, 1956 other known types of illumination and may represent as low as ten per cent of the average cost of maintenance.

Another object of this invention is to provide a cove lighting fixture wherein access to the Wiring and ballasts is gained easily. 7

Another object of this invention is to provide a luminaire which is adapted for fabrication from many different materials, so that the choice of material can be accordingto the dictates of availability and price considerations', the exact sizes and proportions being matters easily determined to suit particular conditions and needs.

Finally, it is an object of this invention to provide a luminaire which is relatively inexpensive and practicable to manufacture, which is simple, safe and convenient to use, and which will give generally etficient and durable service.

With these and other objects definitely in view, this invention consists in the novel construction, combina tion and arrangement of elements and portions, as will be hereinafter described fully in the specification, particularly pointed out in the appended claims, and illustrated in the accompanying drawing which forms a material part of this disclosure and wherein similar characters of reference designate similar or identical elements and portions throughout the specification and thoughout. the different views of the drawing, and in i which:

Fig. 1 is a view, in perspective, showing the cove lighting fixture as mounted upon a wall;

Fig. 2 is a diagrammatic representation of a cove light- .ing fixture, designed to illustrate the direction of the air currents during the operation of the device, thus illustrating why there is a minimum of dust collection in this fixture; Fig. 3 is an isometric view of the lighting fixture, the view being taken from above the level of the fixture, in order to facilitate the illustration of the construction thereof; and

Fig. 4 is a vertical transverse sectional view taken substantially on a center line of the fixture.

Referring now to the drawing in detail, the fixture will be seen to include a vertical side 10 which will be placed against the wall, as illustrated in Fig. l. The fixture may be considered as including a casing and this said side 10 will then comprise the main wall portion of the casing, supporting opposing vertical end plates 12 and a bottom panel 14 which closes a portion only of the bottom side, of the casing. It will be noted that this panel 14 is curved upwardly as at 16 at the edge thereof remote from the side 10. An integral portion of the panel 14 is bent sharply upwardly as at 18, this portion being slightly inclined relative to the vertical and being con tinuous along the length of the fixture.

The end plates 12 are each provided with opposing inwardly turned flanges 20, these flanges serving as means to secure the side 10 to the end plates and also serving to secure the panel 14 to the end plates. Louver slats 22, each being disposed similarly to the inclined portion 18 of the panel 14, are terminally secured to the flanges 20 and extend the full length of thefixture. The side of the casing remote from the side 10 is closed by a front wall 24, which is also secured to the flanges 20, the upper part 26 of this front wall 24 being preferably vertical and terminating in 'a rolled edge. It should be noted that the louver slats 22, the inclined portion 18 and the wall 24 are all parallel to each other and may be considered as a single set of parallel slats.

A plurality of angle braces 28 are terminally secured to the upper end portions of the louver slats 22, by spot welding, as indicated at 30, these upper end portions being turned to comprise outwardly extending flanges 32,

it being noted that the upper end of the portion 18 is similarly outwardly turned and secured to the inner ends of the angle braces 28, while the outer ends of the angle braces 28 are secured to the front wall or slat 24 adj? cent to the upper end thereof. This structure. adds to the rigidity of the fixture, without unduly retarding the flow of air upwardly through the fixture during theoperation thereof.

A plate 34 is secured in inclined relation above the panel 14, the upper end or edge portion of the plate 34 being spot welded or otherwise suitably secured to the upper edge portion of the side 10 of the casing, it being here noted that both the upper edge portion of the plate 34 and the adjacent portion'of the. side 10 are apertured at 36 to provide for suitable attaching means employed to hold the fixture upon a wall. The plate 34 provides support for the lamp brackets 38, the lower end of the plate 34 being rigidly secured to the portion 13. In the embodiment disclosed, a pair of fluorescent lamps 40 are mounted in the brackets 38, above the plate 34, which is, in turn, above the panel 14. Thus it will be seen thatthe side 14?, panel 14, portionig, and plate 34, together with the end plates 12, define a compartment 42 of considerable capacity. In this compartment ballast and wiring elements will be housed, and suitable access panels will be provided, either in the plate 34 or otherwise, in order that the initial wiring and maintenance thereof may be facilitated.

The operation of this invention will be clearly understood from a consideration of the foregoing description of the mechanical details thereof, taken in connection with the above recited objects and the drawing. In

rccapitulation, and by way of further illustration, reference may now be had to Fig. 2 wherein the structure is diagrammatically illustrated, with an air pocket 46 being indicated as surrounding the lamps 40. The air pocket of relatively warm air tends to remain as a continuing envelope for the lamps 40 and the contiguous portions of the fixture, while the air currents 48 are deflected only slightly toward the lamps rather than dipping downwardly into direct contact with the lamps and even below the lamps as ordinarily experienced in lighting fixtures of conventional character. As already explained, this feature is extremely important in lessening the amount of dust and dirt which will accumulate in the. fixture. It is not contended that air in the air pocket 46 will not tend to rise if the air thereabove is cooler to any great degree, but it is contended that there is a definite tendency for the same air to remain more or less stationary as an envelope surrounding the lamps, there being slight currents, of course, within this air pocket itself. The wall 50, against which the side 10 of the fixture abuts, also functions as a boundary for this air pocket. it will also now be clear that the inclined plate 34 serves a triple function in supporting the. lamp. brackets 38, comprising the upper wall-of the compartment 42, andv functioning as a reflector plate to reflect the light from the lamps 40 upwardly and outwardly from the fixture. In fact, it should be noted that the several inclined surfaces in the fixture are arranged. so that there is a maximum tendency for accumulated dust and dirt to gravitate out of the fixture, thus further insuring against the necessity of frequent cleaning, this being particularly true of the angle. braces 28 and louver slats 22, as well as the analogous portions 24 and 18 and the plate 34. The panel 14 is imperforate.

It will be clear that this disclosure is sufiicient to enable anyone skilled in the art to produce and use this invention, and further description would appear to be unnecessary.

Obviously, minor variation from the embodiment dis-. l e m be res ted. 9 tlie t ep rt r rom the spirit of this invention, the. metes and bounds ofwhich should be considered as set forth in the appended claims.

I claim:

l. A cove lighting fixture comprising an open topped casing having a vertical side for 'securement on a wall, said casing having an open portion at the bottom, an imperforate panel closing the remainder of the bottom of the casing, a lamp operatively mounted in the casing vertically above said panel, and louvers in the open portion of the bottom of the casing allowing circulation of air upwardly through said open portion while shielding said lamp from view through said open portion, said louver slats being fixed in said casing.

2. A cove lighting fixture comprising an open topped casing having a vertical side for securement on a wall, said casing having an open portion at the bottom, an imperforate panel closing the remainder of the bottom of the casing, a lamp operatively mounted in the casing vertically above said panel, and louvers in the open portion of. the bottom of the casing shielding said lamp from view through said open portion and allowing circulation of air upwardly through said open portion.

3. A cove lighting fixture comprising an open topped casing having a vertical side for securcment on a. wall, said casing having an open portion at the bottom, an imperforate panel closing the remainder of the bottom of the casing, a lamp operatively mounted in the casing vertically above said panehand louvers in the open portion of the bottom of the casing shielding said lamp from view through said open portion and allowing circulation of air upwardly through said open portion, said casing being substantially triangular in vertical cross-scction, and a substantially imperforate opaque plate fixed in said casing above said panel to form a compartment between the panel and plate for electrical wiring elements.

4. A fixture according to claim 3 and wherein said plate is inclined downwardly from said side toward the open portion of the bottom of the casing.

5. A fixture according to claim 4 and wherein said plate has a polished upper surface to comprise means to reflect light upwardly and outwardly from said vertical side of the casing.

6. A luminaire comprising an open topped casing securable to a wall, an imperforate opaque plate in said casing inclining downwardly from one side of the casing, said casing havingv an open bottom portion extending from the lower edge of said plate to an opposite side of the casing, and a lamp operatively mounted in said casing vertically above said plate.

7. A luminaire according to claim 6 and including fixed louver slats in said open bottom portion shielding said lamp against vision through said open portion.

8. A luminaire according to claim 7 and including a panel below said plate and cooperating therewith to form a compartment in the casing for electrical wiring elements.

9. A luminaire according to claim 6 wherein said casing is substantially triangular in vertical cross-section, having a. vertical side adapted to be secured to a wall, and opposing vertical end plates comprising support means for said plate and lamp.

10. A luminaire according to claim 9 and wherein said lamp and plate are horizontally elongated in the same direction, and louver slats secured in said casing in said open portion and extending parallel to said lamp.

References Cited in the file of this patent UNITED STATES PATENTS 2,205,310 Robinson et al. Jan. 18, 1940 2,322,426 Dreyfuss June 22, 1943 2,345,235 Carter Mar. 28, 1944 2,381,451 Hrabak Aug. 7, 1945 2,560,231 Deane July 10, 1951 2,578,190 Ku tzon Dec. 11, 19.51:

FQREIQN PATENTS 693,611 France Sept. 1, 1930 

